PCSS, Т.13, №3, 2012

Abstracts

D.M. Freik¹, L.I. Nykyruy¹, M.O. Galuschak², G.D. Mateik²

Achievements and Challenges Thermoelectricity II. Basics State of the Theory of Thermoelectric Phenomena (Review)

¹Vasyl Stefanyk PreCarpathian National University 57, Shevchenko Str., Ivano-Frankivsk, 76018, Ukraine, E-mail:fcss@pu.if.ua
²Ivano-Frankivsk National Technical University of Oil and Gas, 15, Carpathian Str., Ivano-Frankivsk, 76001, Ukraine

An overview of classical thermoelectric effects, Fundamentals of the theory and its implementation for the bulk of homogeneous and heterogeneous materials. The parameters as a thermoelectric material and indicated on ways to optimize them. These characteristics thermoelectric efficiency power converters.
Keywords: Thermoelectricity, thermoelectric effects, thermoelectric materials.

V.І. Boichuk, I.V. Bilynskyi, O.A. Sokolnyk

Effect of a Quantum dot Shape on the Optical Absorption Coefficient Due to Intersubband Transitions

Ivan Franko Drohobych State Pedagogical University, 82100, Lviv Region, Drohobych, Stryiska St., app.3, e-mail:sokolnik@gmail.com

We have studied the influence of a quantum dot shape on the energy spectrum of an electron by perturbation theory. In particular, the genesis of the energy levels in cubic, ellipsoidal, cylindrical, and tetrahedral quantum dots by changing the volume of a quantum dot is analysed in detail. A spherically symmetric quantum dot is assumed to be basic. For a spherical quantum dot, the exact solution is obtained from the Schrödinger equation, which yields the energy of an electron. For the ground state and first excited state, we have found the energies and their wave functions. Using the calculated energies and the wave functions of the states, we have determined the selection rules and the dependence of the optical absorption coefficient due to intersubband transitions of an electron in quantum dots of the involved shapes. The specific calculations are performed for GaAs QDs embedded in AlAs semiconductor matrices.
Keywords: quantum dot, the shape of quantum dots, energy spectrum, optical transitions, oscillator strength, the absorption coefficient.

B.M. Ruvinskii¹, M.A. Ruvinskii²

Intraband Dynamic Conductivity of Doped Graphene beyond Linear Response

¹ Ivano-Frankivsk National Technical University of Oil and Gas, 15, Carpatska Str., Ivano-Frankivsk, 76000, Ukraine,
² Vasyl Stefanyk' Precarpathian National University, 57, Shevchenko Str., Ivano-Frankivsk, 76000, Ukraine bruvinsky@gmail.com

The intraband dynamic conductivity of doped graphene was investigated theoretically beyond the approach of linear response of electron subsystem to the incident electromagnetic wave. The dependences of intraband current on the electric field, frequency, temperature and chemical potential were determined with the deviations from the linear approximation of Drude-Boltzmann classical theory of conductivity for the rather strong electric fields and low frequencies. Particularly the saturation of induced current and the non-linear increase of graphene transparency with growth of the wave intensity were obtained also as before in the case of interband conductivity at post-linear response. As contrasted to increase for the interband transitions at fixed intensity the transmission coefficient by the intraband mechanism decreases with rise of the chemical potential and temperature.

R.O. Dzumedzey, L.I. Nukuruy, O.M. Voznyak, T.P. Gevak

Thermoelectric Properties of Solid Solutions PbTe_1-xSe_x

Vasyl Stefanyk PreCarpathian National University 57, Shevchenko Str., Ivano-Frankivsk, 76018, Ukraine, E-mail:fcss@pu.if.ua

The results of research of kinetic parameters (coefficients thermopower, electrical conductivity and thermal conductivity) samples PbTe_1-xSe^x with different composition x = 0.15, 0.25, 0.75, 0.85 and 0.95 produced sintered method. The optimum composition and temperature range of maximum thermoelectric figure of merit.
Keywords: solid solution, kinetic parameters, synthesis.

A.A. Druzhinin ¹, I.P. Ostrovskii ¹, Yu.M. Khoverko ¹, P.G. Litovchenko ³, Yu.V. Pavlovskyj ², N.T. Pavlovska ³, R.M. Koretskyy ¹

Influence of Proton Irradiation on Si-Ge Whiskers Properties

¹Lviv National Polytechnic University, 1 Kotlyarevskii st. , 79013, Lviv, Ukraine
²Drohobych pedagogic university, 24 Ivana Franka st., 82100, Drohobych, Ukraine
³Institute of Physics, NASU, pr. Nauki, 47, Kiev, Ukraine

An influence of and proton irradiation with 6,8 MeV energy and dose up to 1*10¹⁷ сm^-2 as well as annealing at 100 – 280 ^oC on conductance of Si_1-xGe_x (х=0,03) whiskers in temperature range 4,2 -300 К and magnetic field (up to 14 T) have been studied. It was shown that irradiation with dose 5×10¹⁵ р+/сm^-2 does not change the whisker conductance, while irradiation with dose 1×10¹⁶ р+/сm^-2 and annealing leads to substantial changes of resistance and magnetoresistance of Si_1-xGe_x whiskers in temperature range 4,2 - 40 К. The results obtained are explained according to hopping conductance on impurity zone in the crystals.
Keywords: whiskers, proton irradiation, magnetoresistance.

I.R. Zachek¹, R.R. Levitskii², A.S. Vdovych²

Longitudinal Relaxation of Quasi-One-Dimensional CsH₂PO₄ Type Ferroelectrics

¹Lviv Polytechnic National University , 12 Bandery Street, 79013, Lviv, Ukraine
²Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine 1,Svientsitskii Street, 79011, Lviv, Ukraine

Dynamic model of deformed quasi-one-dimensional ferroelectrics with hydrogen bonds is proposed. On the basis this model within the two-particle cluster approximation with taking into account short-range and long-range interactions and strains and in the frames of Glauber method with taking into account dynamics of strains via Newtonian equations of motion a dynamic dielectric permittivity for both mechanically clamped and free crystals are derived. It is shown, that at proper set of the model parameters it is proper description of experimental data for the set of partially deuterated Cs(H_1-xD_x)2PO₄ ferroelectrics by proposed theory.
Keywords: ferroelectrics, cluster approximation, dynamic dielectric permittivity, piezoelectric resonance.

V.I. Mandzyuk¹, Yu.O. Kulyk², N.I. Nagirna¹, I.P. Yaremiy¹

The Porous Carbon Materials Structure by X-ray Diffractometry and Small Angle X-ray Scattering Methods

¹Vasyl Stefanyk Precarpathian National University, 57 Shevchenko Str., Ivano-Frankivsk, 76025, Ukraine
²Ivan Franko National University, 8 Kyrylo and Mefodiy Str., Lviv, 79005, Ukraine

The effect of carbonization temperature of vegetable raw material on the porous structure of the carbon material got from them is explored in the work. It is set, that carbon material is characterized by disordered structure, in which graphite-like clusters of 20-30 Å are formed at growth of carbonization temperature. The growth of carbonization temperature results in development of material porous structure also, that is reflected in the increase of both surface area and pore volume. It is shown, that carbonized material is characterized by the presence of mass and surface fractals, mass fractals are formed from primary carbon nanoclusters of 27-45 ?. The fractal dimension of mass fractals decreases at increase of temperature that satisfactorily correlates with the change of material porous volume.
Keywords: porous carbon material, X-ray diffractometry, small angle X-ray scattering, fractal structure.

V.S. Bilanych, R.Y. Buchuk, К.V. Skubenych, I.I. Makauz, І.P. Studenyak

Relaxation Processes in Silver Containing Superionic Composites in the System Ag3AsS3-As2S3

Uzhgorod National University 88000, Uzhgorod, Pidhorna str. 46, vbilanych@gmail.com

The mechanical properties of glasses in the system Ag₃AsS₃  – As₂S₃ are investigated by method of internal friction. The internal friction and shear modulus of these materials were measured in the temperature range 100 – 300 K at frequencies of deformation of 10 – 50 mHz.. The maxima of internal friction of relaxation type are revealed. It is found, that the concentration change of parameters the process of mechanical relaxation of glasses (Ag₃AsS₃)_х(As₂S₃)_100-х in the range 20 atm.% Ag₂S has a threshold character. It is shown, that this feature may be related to changes in the structural unit, which makes the process of dissipation of mechanical energy in the temperature range 100 – 300 K.
Keywords: relaxation, superionic composites, internal friction.

O.V. Morushko, I.M. Budzulyak, B.I. Rachiy, L.S. Yablon, O.M. Hemiy

Thermogravimetric Studies Composites TiS₂ <C>

Stefanyk Precarpathion National University, 57, Shevchenko Str., Ivano-Frankivsk, 76025, Ukraine

Curves were analyzed differential-thermal analysis (DTA) and thermogravimetry (TG) for composites TiS₂ < carbon material> using laser-irradiated TiS2. It is shown that the structure of the composite TiS₂<C> most intensively formed in the temperature range 425 – 500 K and in the range 750 – 1300 K is joining carbon atoms in the interlayer space structure of TiS₂.

B.P. Koman

The Peculiarities of Spectars of Thermostimulated Depolarization of X-Rayted Irradiations Structures Si - SiO2

Ivan Franko Lviv National University, department of electronics, 50, Dragomanova Str.,Lviv,79005,bogdan_28@mail.ru

The patterns of spectars of thermostimulated depolarization (TSD) of the presource and x-rayted irradiations structures Si-SiO₂ has been researched. The experimental curves j(Т) are demonstrating two specifical maximums in the area of 360 (LT-) and 450 K (HT-maximum)/ on the base of solution Fredholm integral equation of the 1st stage which describes experimental spectras TSD, the energetic spectra density of the states defects has been calculated, which form electretic state in the area peculiar maximums j(Т). The energy of the activation and frequency factors of the appropriate defects had been valued/ The interpretation of the results had been done with the use of the model of the classic ion’s traps, on the interphase border Si-SiO₂ also including the mechanisms of the volumed transport of the ions (H+, Na+) in the structural network SiO₂.

V.S. Bushkova

Determination of The Initial Magnetic Permeability of (1-x) MgFe₂O₄ – x BaTiO₃ Composite Systems

Vasyl Stefanyk PreCarpathian National University 57, Shevchenko Str., Ivano-Frankivsk, 76025, Ukraine, E-mail:bushkovavira@rambler.ru

In this paper the (1-x) MgFe₂O₄ – x BaTiO₃ composite systems in the form of toroid were obtained by sintering at temperature 1300 °C. The inductance of coils based on these samples with different contents of BaTiO₃ was determined experimentally at room temperature. It was shown that with increasing concentrations of ferroelectrics in the composite decreases initial magnetic permeability. It was found that magnetic permeability of ferrite component in the composites is about 13.
Keywords: magnetoelectric material, ferrite, inductance of coil, initial magnetic permeability.

V.V. Kurovets, V.D. Fedoriv

The Mechanism of Amorphization in Single Crystalline Ferrite-Garnet Films by Helium Ions

Vasyl Stefanyk Precarpathian National University, 57, Shevchenko Str., Ivano-Frankivsk, 76000, Ukraine, e-mail:kurovec@i.ua

The mechanism of radiation defect formation in single crystalline ferrite-garnet films implanted by helium ions with an energy of 100 keV are investigated. Found that implantation of YIG films by helium ions in the dose range D = 1•10¹⁵ - 1•10¹⁶ сm^-2 does not lead to the formation of a continuous amorphous layer, and the degree of amorphization of YIG films increases linearly from 0.02 to 0.21. Continuous amorphous layer is formed if D ≥ 8•10¹⁶ Не+/сm².
Keywords: yttrium-iron garnet, ion implantation, radiation defects, amorphization.

Ya.P. Saliy, D.M. Freik, I.S. Bilina, O.L. Sokolov, V.Yu. Potyak

Features Orientational Symmetry Vapor-Phase Condensates CdTe on Chipped Mica-Muscovite

Physical-Chemical Institute at the Vasyl Stefanyk PreCarpathian National University 57, Shevchenko Str., Ivano-Frankivsk, 76018, Ukraine

Using atomic force microscopy peculiarities of formation of thin-film cadmium telluride nanostructures on substrates of mica-muscovite obtained in quasiclosed volume by "hot wall". Lowering of symmetry nanoformations with increasing temperature evaporation and increase the time of deposition of condensate.
Keywords: cadmium telluride, nanostructure growth processes, vapor phase, hot wall.

O.M. Bordun, I.V. Dovga, I.O. Bordun

Dispersion of the Refractive Index of Thin Y₂O₃ Films Obtained by Different Methods

Ivan Franko Lviv National University, 1, Universytetska Str., Lviv, 79000, Ukraine, e-mail:bordun@electronics.wups.lviv.ua

The dispersion of the refractive index of thin Y₂O₃ films, obtained by the method of the discrete evaporation and RF-spattering in different atmospheres, is investigated. The dispersion curve in the visible region, irrespective of a production method, is mainly determined by the transition from the top of the valence band formed by the 2p-states of oxygen to the bottom of the conduction band formed by the 4d5s-states of yttrium. The parameters of the one-oscillator approximation are determined, the dispersion energy, ionicity degree and coordination number are calculated.
Keywords: thin film, yttrium oxide, dispersion, refractive index.

R. Ganich, V. Artemchuk

Physical Properties of the Films Fe-Ni-P, Obtained by Pulsed Current

Dnepropetrovsk national university of railway transport named academician V. Lazaryan, Dnepropetrovsk, street of akad. V. Lazaryan, 2. E-mail:art_vv@ukr.net, (067)5659803

The results of study of the effect of pulse current on structure and physico-mechanical properties of electrodeposited Fe-Ni-P alloys. It is shown that their structure and properties significantly affect not only the concentration of phosphorus, but the equilibrium crystallization conditions caused by pulsed mode of deposition. Found that the coercivity and saturation magnetization films deposited at high values of cathodic polarization higher than the films obtained in a non-equilibrium conditions.

V.M. Pylypiv¹, О.Z. Garpul¹, B.K. Оstafiychuk¹, V.О. Kotsubynskii¹, Artur Blachowski², Krzysztof Ruebenbauer², Jan Zukrowski³

Changes in Magnetic Microstructure of Surface Layers Iron Garnet Films, Initiated by Implantation of Si+ Ions

¹Precarpathion national University named after Vasyl Stefanyk, 57 Shevchenko Str., Ivano-Frankivsk, 76025, Ukraine
²Moessbauer Spectroscopy Laboratory, Pedagogical University, PL-30-084 Kraków, ul. Podchorazych 2, Poland
³Solid State Physics Department, Faculty of Physics and Applied Computer Science, AGH University of Science and Technology PL-30-059 Kraków, Al. Mickiewicza 30, Poland, ogorishna@ukr.net

This paper presents the results of studies of near-surface layers of epitaxial monocrystalline films of iron-garnet (YIG, Y₃Fe₅O₁₂), implanted Si+ ions with energy 90 keV and doses of 1*10¹³, 6*10¹³, and 2*10¹⁴ сm^-2, using Mössbauer spectroscopy of conversion electrons. Analyzed characters of dose dependency component Mössbauer spectra and by comparing them with previously obtained results of simulation and X-ray diffractometry.
Keywords: yttrium-iron garnet, ion implantation, conversion electron Mossbauer spectroscopy.

V.P. Kurbatskiy, A.V. Korotun, E.L. Zhavzharov, V.V. Pogosov

Optical Absorption in Metal Nanocomposites

Zaporizhzhya National Technical University, Zaporizhzhya, Ukraine, e-mail:vpogosov@zntu.edu.ua

The optical properties of metal nanoparticles in a dielectric matrix. To assess the quantum effects applied analytical expression for the dielectric function of the metal particle-parallelepiped. Calculated absorption coefficient for composites with particles of different metals in different matrices, and a comparison with experimental data.
Keywords: Optical absorption; nanocomposite; dimensional quantization.

O. Hutsul¹, V. Slobodyan², M. Shaplavskiy¹

Features of the Spectral Characteristics of Metal-Film-Metal for Films С₁₇Н₃₅СООNa + С₁₁Н₂₃СООNa Range of Sound Frequencies

¹Bukovynskyy State Medical University, Chernivtsi, Ukraine, e-mail:oksana.v.s @ mail.ru
²Chernivetskiy National University. Semiconductors and Nanostructures, Chernivtsi, Ukraine

Spectral dependence of nonlinear wills-voltage characteristics depending on the magnitude of the electric field, which changes the distance in the metal-film-metal, resulting in deformation of near and distant relationships between atoms in the film.
Keywords: electrical properties, thin films, sodium stearate, the system metal-film-metal? current-voltage characteristics.

L.M. Gumenyuk¹, I.I. Grygorchak², I.M. Budzulyak¹, R.V. Ilnytskyy¹

Current Formation by Intercalation Process in Nano Dispersed TiO₂ Doped by Zirconium

¹Vasyl Stefanyk Precarpathian National University, Ivano-Frankivsk, Ukraine. E-mail:glmll@i.ua
²National University «Lvivska Politechnika»

This paper describes general study of TiO2 doped Zr by sol-gel technology from its synthesis and to its use as electrode material in the LPS. Particular attention has material <TiO₂> Zr annealed at 850 0С, which showed capacity up to 1000 A•h/kg.

A.O. Shyichuk

Theoretical Computations of f-d Transitions of Tb³⁺ Ions in Sr₃Y₂(BO₃)₄:Tb³⁺ Via ab initio and DFT Methods

Vasyl Stefanyk’ Precarpathian National University, 57, Shevchenko Str., Ivano-Frankivsk, 76025, Ukraine

The computations of energies of f-d transitions and respective wavelengths in Sr₃Y₂(BO₃)₄:Tb³⁺ were performed via HF, mp2 and mpw2plyp methods in Gaussian09 software package using Stuttgart-Dresden pseudopotentials and appropriate basis sets. The obtained energy values are in significant difference with the experimental ones. It was shown, that for Tb3+ ions in different coordination surrounds the energies of f-d transitions are different. The energy differences are rather small and this fact agrees with experiment. It means that the described approach is useful however some other computational methods and more sophisticated software should be used.
Keywords: lanthanides, terbium (III), luminescence, calculations, theory.

N.P. Gorbachuk

High Temperatures Thermodynamic Characteristics of rare – earth Metals Germanides RGe_2-x

I.N. Frantcevich Institute for Problems of Materials Science, National Academy of Science of Ukraine, 3 Krzhizhanovsky str, 03142, Kyiv, e-mail:bas@ipms.kiev.ua

A procedure of the heat capacity and enthalpies of melting estimation of REM digermanides is suggested. The temperatures dependences of heat capacity and enthalpies, entropies of melting for the germanides RGe2-x (R=Ce, Nd, Pm, Sm, Tb, Dy, Er, Tm) were obtained.
Keywords: germanide, enthalpy, heat capacity, entropy.

G. Korenkova¹, O. Tadeush²

Electronic Structure of Vanadate CeVO4

¹Odessa National I.I. Mechnikov’s University Odessa, Ukraine, Dvoryanskaya str. 2, e-mail:av_korenkova@mail.ru)
²Southern National Pedagogical University named after K.D. Ushinskogo 65091, Odessa, Staroportofrankovskaya stк, 26

Electronic structure of the CeVO₄ ortovanadat is investigated using as the band-structure LAPW-calculations. The information about the charge and spins description of atoms, and also about law’s conformities of power zones forming of the valence states in an oxide CeVO₄ has been receipt.
Keywords: electronic structure, vanadate, LAPW- calculations.

V.M. Boychuk, M.P. Vadyuk, G.Ya. Gurgula, N.D. Freik

Crystal Model Defective Subsystem in Iron Doped Zinc Selenide Crystals of ZnSe: Fe

Physical-Chemical Instituteatthe‘VasiliyStefanyk’PrecarpathianNationalUniversity, 201, GalytskaStr., Ivano-Frankivsk, 76000, Ukraine, E-mail:freik@pu.if.ua

The crystal-quasichemical formulae of doping at the Crystals n-ZnSе:Fе аnd p-ZnSе:Fе are suggested. The dependence on point defects concentration, on free charge carrier concentration and Hall concentration of the degree of nonstoichiometry (α, β), zinc in knots of a crystalline lattice (γ) and in interstices (ε), and also coefficients of disproportionation of interstitial atoms of zinc (δ) and vacancies of zinc (μ) are calculated.

I.F. Myronyuk, V.V. Gumenyak, V.I. Mandzyuk, N.A. Bezruka

The Structure and Morphology of Al₂O₃ Particles Obtained at Different Conditions of Gas-Phase Synthesis

Vasyl Stefanyk Precarpathian National University, 57 Shevchenko Str., Ivano-Frankivsk, 76025, Ukraine

The structural-chemical processes at the fumed synthesis of high-dispersed Al₂O₃ in hydrogen-air flame are explored in the work. It is found out, that the contact of AlCl₃ steam with the components of high temperature flame results at first in formation of co-ordinating saturated hydrocomplex [Al(OH)₆] ^3-, from which the particles of amorphous aluminum hydroxide Al(OH)₃ are formed as a result of condensation. The subsequent structural ordering and serial phase transformations provide formation of crystalline phases Al₂O₃ in powder material. The presence of χ-, γ-, δ-, and θ-Al₂O₃ is registered in got high-dispersed product at the flame temperature of 1200°C. γ-, δ-, θ-, and α-Al₂O₃ are the dominant phases in material synthesized at temperature of 1320°C. The fumed method enables to get aerogel-like material with a specific surface 86-107 m²•g ^-1, in which the fractal lace of aerogel are formed from particles with size of 15-45 nm.
Keywords: alumina, fumed synthesis, hydroaquacomplex precursors, crystal modifications, aerogel-like material.

O.M. Duda¹, I.J. Kostiv²

Interaction of Magnesium Chloride Solutions with Incarbonic Dolomite

¹Vasyl Stefanyk’ Precarpathian National University, 57, Shevchenko Str., Ivano-Frankivsk, 76025, Ukraine
²The State Scientific Research Institute of Gallurgy, Kalush

Interaction of aqueous solutions of magnesium chloride with different concentrations dekarbonizovanym dolomite. A study of the interaction products, the composition of the gas phase, which is formed by heating these products. The optimum conditions of thermal decarbonization of natural dolomite to obtain active magnesium oxide, establishing the possibility of obtaining magnesia binders. Magnesia low-active forms of magnesium oxide can be used to obtain refractories.
Keywords: incarbonic dolomite, magnesium chloride solutions, magnesium binders.

Z.F. Tomashyk¹, І.B. Stratiychuk¹, S.І. Budzulyak¹, А.S. Kravtsova¹, V.М. Tomashyk¹, S.M. Galkin², О.О. Sosnytska², S.М. Kalytchuk¹, D.V. Korbutyak¹, L.А. Demchyna¹

Influence of Mechanical and Chemical Treatments of Surface on Low-Temperature Photoluminescence Spectra of Znse Crystals

¹V.Ye. Laskaryov Institute for Semiconductor Physics of National Academy of Sciences of Ukraine, 41, Nauki ave., Kyiv, Ukraine, e-mail:ztomashyk@gmail.com
²Instytut scintillation materials NAS of Ukraine, Lenin Av., 60, Harkiv, 61001

Compositions of polishing solutions for undoped and doped ZnSe single crystal and methods of receiving mirror polished surface by chemical etching with bromine emerging solutions H₂O₂-HBr-ethylene glycol have been developed. Using the proposed technique significantly (in 5 times) increases the integrated low temperature PL intensity by reducing of nonradiative losses at the surface of zinc selenide, which indicates the formation of high-surface substrates, has been found. Low-temperature (T = 5 K) photoluminescence spectra of crystals have been studied, specific PL bands in the exciton and impurity regions of the spectrum have been identified, intensity and energy position dependences of photoluminescence lines depending from type of dopant material and method of mechanical and chemical processing of these materials have been analyzed.

S.G. Orlovskaya, M.S. Shkoropado, F.F. Karimova

Growth Kinetics of Oxides Structures on Refractory Metal Surface During Heating in Air

Odessa National I.I. Mechnikov’s University Odessa, Ukraine, Dvoryanskaya str. 2, 65082, (048) 723-62-27, svetor@rambler.ru

The growth characteristics of oxide structures on the surface of metal wires (tungsten, molybdenum), heated electrically in air, are studied. It is found that at first oxide microfilaments appear on the primary oxide film formed on tungsten surface. Then they grow and transform into branched crystalline structures. When heating molybdenum wire, the oxide platelets are formed, which are oriented in different directions and with time link each other as a result of growth. The temperature histories of crystals formation and growth are defined as well as their growth rates. It is found that considered structures consist essentially of tungsten trioxide and molybdenum trioxide.
Keywords: high temperature oxidization, tungsten, molybdenum, oxides, crystalline structures.

S.A. Sveleba, I.V. Karpa, I.M. Katerynchuk, I.M. Kunyo, O.I. Fitsych

Size Effects in Crystals [N(CH3)4]2MnCl4

Lviv Franco National University, Department of Non-Linear Optics hen. Tarnavskogo st 107, Lviv, UA79017

In this paper the investigations of thickness (da, db, dc) of the crystals [N(CH₃)₄]₂MnC_l4 on the incommensurate phase temperature range existence are presented. It was established that the expansion of temperature range existence of the incommensurate phase is accompanied with reducing the size of the crystals. The temperature of phase transitions Ti and Tc is grown. The new long-period commensurate phase appears on the phase diagram.

D.M. Freik¹, V.M. Chobanyuk¹, O.S Krunutcky², I.V. Gorichok¹

Photovoltaic Solar Energy Converters Based on Cadmium Telluride II. The Main Achievements and Current Status (Review)

¹Vasyl Stefanyk PreCarpathian National University 57, Shevchenko Str., Ivano-Frankivsk, 76018, Ukraine, E-mail:fcss@pu.if.ua
²Ivano-Frankivsk National Technical University of Oil and Gas, 15, Carpathian Str., Ivano-Frankivsk, 76001, Ukraine

The analysis of advances in solar energy. The main attention is paid to physical and chemical properties, methods for thin film solar modules and components based on them. The analysis of the prospects for their manufacture and use.
Keywords: Solar energy, solar structure, solar cells, cadmium telluride.

L. Kozak, O. Kozak

Polymorphic Transformation and Flexibility

Ivano-Frankovsk State University of the Oil and Gas, Karpatska Str., 15, 76000, Ukraine

On the two-dimensional model of the crystal it was shown that the crystal lattice can be stable or unstable depending on the temperature. When crystal lattice appears during crystallization it is stable. When the temperature drops crystal lattice stays unstable. The conclusion has been done, that the cause of the process of low temperature plastic deformation is crystal lattice instability, similar to polymorphic transformations. Both the polymorphic transformation and plastic deformation are the identical processes of atomic plane shear. But the reasons of crystal lattice destabilization in both cases are different.

V.D. Fedoriv, N.V. Stashko, I.P. Yaremiy, V.V. Moklyak

The Forming the Structure of the Yttrium Iron Garnet on the basis of the Feedstock got by the Sol-Gel Method

Vasyl Stefanyk PreCarpathian National University, 57, Shevchenko Str., Ivano-Frankivsk, 76000, Ukraine, E-mail:nstashko@gmail.com

By the sol-gel method of autocombustionan initial charge was synthesized for a receipt a polycrystalline Yttrium Iron Garnet which was annealed in different temperatures. It was set that forming of the monophase system Y₃Fe₅O₁₂ begins at temperatures above 800 ºС. It was discovered that pH of the solution of initial reagents influences on the process of autocombustion and crystallization the Garnet in further annealing. An acid environment promotes the formation of the monophase system Y₃Fe₅O₁₂ already at 900 ºC.

D.U. Petryna, O.L. Kozak, U.D. Petryna

Estimation of Degradation of a Trumpet Steel a Method of an Internal Friction

Ivano-Frankivsk State University of the Oil and Gas, Karpatska Str., 15, 76000, Ukraine

At the latest stage of oil and gas pipelines operation plays an important role to establish the degree of degradation of various properties of pipe steels, because the substantiation of the further safety work of pipelines should be considered not so target , and current characteristics of operated metal. With that end in view in work the equipment is developed for studying degradation processes of pipe steels by a method of an internal friction. This method can be carried out qualitative assessment of degree degradation of pipe steel 17Г1С. Keywords: kinetics of ageing of steels, physical and mechanical properties of steels, electrochemical properties of steels, the amplitude of stress, logarithmic decrement of fading oscillations.

Yu.V. Lysyuk, V.V. Prokopiv

Synthesis and Thermoelectric Properties of Antimony and Bismuth Doped of Lead Telluride

Vasyl Stefanyk Prekarpathian University, Shevchenko Str., 57, Ivano-Frankivsk, 76025, Ukraine, E-mail: fcss@pu.if.ua

The results of the study of thermoelectric properties of undoped lead telluride samples and doped with antimony or bismuth and fabricated by metal-ceramic method. Revealed a correlation between technological factors and thermoelectric parameters of the materials.

V.Ya. Loburak, I.Yo. Perkatyuk

Influence of Structure of the Surface Friction on Wear Resistance of the Material

1Ivano-Frankivsk National Technical University of Oil and Gas, Ivano-Frankivsk, Ukraine 2‘Vasyl Stefanyk’ Precarpathian National University, Ivano-Frankivsk, Ukraine

We investigated process of wear in dry friction, based on the concepts of energy conversion of plastic deformation in the contact zone in a energy dislocation in the near-surface zone of friction.

M.D. Buchkovska, R.I. Bihun, Z.V. Stasyuk, B.R. Penyukh, Ya.А. Pastyrsky

Percolation Process in Electron Transport Properties of Manganese Films

Ivan Franko’ Lviv National University, 50, Dragomanova Str., Lviv, 79005, Ukraine

The electrical properties of quench condensed ultrathin manganese films were investigated. Predeposited aluminum underlayers accelerate metallization process in manganese films. The main models of classical and quantum electron transport in metal films were used in explanation of resistivity size dependences. Metal electron transport character was explained in the framework percolation theory. Aluminum underlayer helps manganese film 2D formation.

V. F. Zinchenko¹, V. E. Chygrynov², O. V. Mozkova³, I. R. Magunov¹, Ye. V. Timukhin¹, L. V. Sadkovska¹

Effect of The Interaction In System ZnSe-Ge on the Properties of Composites and Obtained from them Thin-Film Coatings

¹ A. V. Bogatsky Physico-Chemical Institute of NAS of Ukraine, 86 Lustdorfska Doroga Str., 65080, Оdesа, Ukraine, vfzinchenko@ukr.net
²Odesa National University, 2 Dvoryanska Str., 65044, Оdesа, Ukraine
³Central Design Office "Аrsenal", 8, Moscovska Str., 02010, Kyiv, Ukraine, borisgor@i.com.ua

The character of the interaction and thermal evaporation in vacuum of the composites of ZnSe– Ge system is studied and CVD mechanism is revealed. Thin-film coatings obtained from composites exhibit high optical and operational parameters and regarded as promising ones for interference optics of the IR interval of a spectrum.
Keywords: composite, optical properties, thermal evaporation, thin-film coatings, IR optics.

V. Zabludovsky, D. Boroschuk

Electrocrystallization Copper Films in the External Constant Magnetic Field

Dnepropetrovsk national university of railway transport named academician V. Lazaryan, Dnepropetrovsk, street of akad. V. Lazaryan, 2. e-mail:dmitrii_boroshuk@mail.ru

One of the methods of getting thin metal films that have definite structure and characteristics is using the external static magnetic field in the process of electrolytic deposition. The aim of the study is to analyze the influence of the external constant magnetic field on the process of electrolytic deposition, the structure and some physical characteristics of copper films. Convective streams (mixing) appear when the static magnetic field is used in the process of electric deposition. This changes the kinetics of electrode processes and copper coating surface morphology, and the microhardness of all studied samples increases.

G. Ilchuk, V. Kusnezh, R. Petrus’, T. Stanko

The Vapour Thermal Synthesis of CdTe Films from Elementary Components

Department of Physics, Lviv Politechnic National University 12, S. Bandera Str., Lviv, 79013, Ukraine, e-mail:gilchuk@polynet.lviv.ua

The opportunities for synthesis of cadmium telluride (CdTe) semiconductor films by annealing of the cadmium (Cd) metallic films on glass substrates in the tellurium (Te) vapors were studied. The experiment of annealing-tellurisation (tellurium transfer to the plate with cadmium and expected CdTe synthesis) was preceded by theoretical analysis of partial pressures of the Te vapour above the Tesol, the Cd above the Cdsol, the Te above the CdTesol, the Cd above the CdTesol for the case of congruent sublimation and by the choice of thermal annealing conditions from the results of conducted analysis. With the use of the scanning electronic microscope the surface morphology of the initial Cd films and annealed films were investigated, and quantitative composition was determined from spectra of the characteristic X-ray radiation. Optical properties were investigated.
Keywords: CdTe, II-VI compounds, thin films, vapor pressure.

V.V. Brus, Z.D. Kovalyk, V.V. Khomyak, V.M. Kaminskiy

Electrical Properties of the ZnO/InSe and ZnO/GaSe Heterojunctions

1Frantsevich Institute for Problems of Materials Science, NAS of Ukraine, Chernivtsi Department, 58001 Chernivtsi, Ukraine, 2Yuriy Fedkovych Chernivtsi National University,58012 Chernivtsi, Ukraine

The main electrical properties of the n-ZnO/n-InSe and n-ZnO/p-GaSe heterojunctions prepared by spray pyrolysis deposition of a ZnO thin film onto freshly cleaved InSe and GaSe single crystal substrates were investigated. The dominant current transport mechanisms in the heterojunctions at reverse bias were established.
Keywords: ZnO, thin film, InSe, GaSe.

B. Pavlyk, A. Lenovenko, A. Hrypa

The Investigation of the Influence of X-ray Irradiation and Weak Magnetic Field on the Parameters Stability of Transistor Temperature Sensors

Ivan Franko National University of L’viv Tarnavs’kogo, st, 107, 79017 L’viv, Ukraine

The parameters with which the transistors that are suitable for use in thermometry must be complied are presented. The influence of X-ray irradiation and weak magnetic field on electrophysical parameters of thermal sensors has been investigated. From the analysis of current-voltage and capacitance-voltage characteristics it is shown that at the initial stage of X-ray radiation influence the increase of efficiency of recombination processes in the space charge region (SCR) and slight decrease of the direct current are observed. It can be explained by the effect of destruction of metastable structural defects of the base. The external magnetic field (B=0,17 Tl) does not change the efficiency of recombination processes in SCR, but make the impact on the diffusion component of direct current through p-n-junction. The effect of X-rays (D<325 Gr) and weak magnetic field practically did not change the temperature response curve, leading to a conclusion about the parameters stability at above conditions.
Keywords: thermal sensors, X-rays, magnetic field, p-n-junction.

S.P. Novosyadlyy, T.P. Kindrat, T.R. Sorokhtey, Yu.V. Voznyak

Comparative Analysis of Current Silicon Technology and Gallium Arsenide Submicron Structures of High-Speed Digital Large Integrated Circuits

Precarpathian National university after Vasyl Stefanyk 57 Shevchenka str, Iano-Frankivsk, Ukraine, e-mail:kindrat@i.ua, majesty@nashemisto.if.ua

In this article shown tendencies and prospects of developments of transistor structures for the industrial making of competition silicic and gallium arsenide speed digital LSI - element-technological and designer base of facilities of the computing engineering (FCE) supercomputer of higher generation. In this article unique properties are illuminated both silicium and gallium arsenide submicrometer technologies.

D.М. Freik, B.S. Dzundza, A.I. Tkachuk, T.P. Kushnir

Measurements Automation of Electrical Parameters Semiconductor

Vasyl Stefanyk PreCarpathian National University 57, Shevchenko Str., Ivano-Frankivsk, 76025, Ukraine, E-mail:freik@pu.if.ua

Method for measuring electrical parameters of semiconductor films. Presented electrical circuit and developed a computer program that enables automation of measurement, registration and initial data processing, with the possibility of charting time dependencies for a preliminary analysis of the experimental data already in the process of measurement.

S.I. Yushchuk, S.O. Yuryev

Diagnostics of Magnetic Anisotropy of Ferrogarnet Films

National university “Lvivska politehnika” 12, Bandery St, Lviv, 79046 e-mail:syuryev@mail.ru

Reasons of origin of monaxonic magnetic anisotropy (MMA) are analysed in epitaxial ferrogarnet films. The method of measuring of the field ( ) of MMA is offered. In basis of method determination is fixed with the help of Faraday effect of dependence on longitudinal receptivity of film standard from the transversal permanent magnetic field which is perpendicular to the axis of the easy magnetizing. The flow-chart of the measuring setting is broughted. The relative error of measuring does not exceed 5 %.

P.V. Galiy¹, T.M. Nenchuk¹, О.P. Poplavskyy², О.Ya. Tuziak³

Scanning Electron and Atomic-Force Microscopies of the CsI Films Surface Radiolisys at the Highly-Intensive Electron Irradiation

¹Ivan Franko Lviv NationalUniversity, 50 Drahomanov Str., Lviv, 79005
²Vasyl Stefanyk PreCarpathian National University, Physicotechnical faculty, 57 Shevchenko Str., Ivano-Frankivs’k, 76000, e-mail:galiy@electronics.wups.lviv.ua

The destruction, defects formation processes and radiolysis mechanisms of the CsI films surfa¬ces under mean energies electron irradiation were investigated by methods of scanning electron and atomic-force microscopies. The results are presented for the wide range of dose rates and irradiation doses. Dose rates and doses, at which nanophase and nano-, and micro pores formations occure at the surface, were estimated. It was obtained for the first time by scanning atomic-force microscopy at the nanolevel. Also electron irradiation doses, when radiolysis of the CsI films surface takes place with segregation of nano- or microphases and assembling of nanoformations, were determined.